1. Field of the Invention
The present invention relates to a radiation imaging device, a radiation imaging system, a radiation imaging device control method, and a non-transitory computer readable medium storing a radiation imaging device control program. In particular, the present invention relates to a radiation imaging device, a radiation imaging system, a radiation imaging device control method, and a non-transitory computer readable medium storing radiation imaging device control program that may image still images and video images.
2. Description of the Related Art
Heretofore, a radiation imaging device has been known that, in order to image a radiation image, detects radiation that has been irradiated from a radiation irradiation device and has passed through an imaging subject, with a radiation detector. This radiation imaging device performs imaging of radiation images that are still images and also, for example, imaging of video images in which plural radiation images (still images) are successively imaged.
This radiation imaging device includes the radiation detector that detects radiation. The radiation detector is a detector that includes pixels and amplification circuits or the like; each pixel includes a photoelectric conversion element, a storage capacitor and a switching element. The photoelectric conversion element generates charges due to irradiation of radiation or illumination of light converted from radiation. The storage capacitor retains and accumulates the charges generated by the photoelectric conversion element. The switching element reads the charges out from the storage capacitor and outputs electronic signals that correspond to the charges. Each amplification circuit is configured by an integration circuit, which integrates charges that correspond to the electronic signals outputted from a switching element provided at a pixel, and outputs electronic signals for which the integrated charges are amplified.
In a case in which a large number of switching elements such as TFTs or the like are arranged in a matrix pattern, plural gate lines for turning the switching elements ON and OFF, and plural signal lines for transferring the signal charges from pixels whose switching elements have been turned ON, form an intersecting arrangement, and thus, parasitic capacitances occur. The amplitude of a voltage applied to a parasitic capacitance occurring at intersecting position of the gate line and signal line connected to a switching element changes in a case in which the switching element is turned ON or turned OFF. Thus, induced charges are produced at the parasitic capacitance, and these charges are superimposed on the charges being transferred through the signal line (signal charges for a radiation image) in the form of a noise component which is referred to as a “feedthrough component”. Since the charge amounts retained and accumulated at the individual pixels of the radiation detector are very small, the signal charges being transferred along the signal lines are of the same order as the order of the feedthrough components. Therefore, the effects of the feedthrough components cannot be disregarded.
Accordingly, as technologies for eliminating (cancelling) the feedthrough components, for example. Japanese Patent No. 3,696,176 and Japanese Patent Application Laid-Open (JP-A) No. 2010-268171, discloses such the technologies.
In general, in imaging a video image, plural frames (a plural number) of still images are successively imaged. In cases of imaging these video images, it is desirable to increase the frame rate. In particular, higher frame rates have been called for in recent years.
However, the effects of the above-described feedthrough components may become larger in a case of video imaging. In video imaging, because plural images (frames) are being imaged, doses for each frame are smaller than in a case in which imaging still images. Consequently, the charge amounts retained and accumulated at the pixels become smaller, and the effects of the feedthrough components become relatively larger.
The present invention provides a radiation imaging device, radiation imaging system, radiation imaging device control method, and non-transitory computer readable medium storing radiation imaging device control program that may suppress feedthrough components in imaging video images.